The Many Modes of a Camera

Our $100 point-and shoot camera has Auto, Program, Portrait, Smart Shutter, Low Light, Fisheye Effect, Miniature Effect, Toy Camera Effect, Monochrome, Super Vivid, Poster Effect, Color Accent, Color Swap, Snow, Fireworks, Long Shutter, and Stitch Assist modes. That's overwhelming to me. On top of that, none of those modes offer true control. That's of course where the term "point-and-shoot" came from. You point the camera and take a picture without concerning yourself with how the picture is actually made. That's all that most people want. And that's not limited to people with $100 cameras or cell phones. There's people out there that spend thousands of dollars on camera gear and never do more than "point-and-shoot." I assume that if you've made it this far then you want to learn more than those people.

Hopefully your camera has a Program (P), Aperture Priority (A or Av), Shutter Priority (S or Tv), and Manual (M) modes. You might have other modes on your camera (like auto mode or running man mode), but I'm going to focus on the four modes listed above.

Program (P) Mode

What is it?
It's an automatic mode. The camera picks the aperture and shutter speed. The ISO can be set to auto or adjusted by the user. Basically, it allows the camera total control over an exposure.

Who's it for?
Anyone that wants to take a picture and not worry about exposure settings. For example, a novice or expert who wants a usable picture where they only have to worry about framing.  

What benefits does it offer?
Ease of use. Allows the photographer to focus on framing. 

Aperture Priority (A or Av) Mode

What is it?
This is a semi-automatic mode. The user chooses the aperture and the camera chooses the shutter speed. Once again ISO can be set by the user or the camera. The camera still has control over the final exposure, but the user has more input.

Who's it for?
Anyone that wants to choose their depth of field and/or aperture but still wants the convenience of an automatic mode.

What benefits does it offer?
Ease of use. Allows control of depth of field but still offers automatic exposure.

Shutter Priority (S or Tv) Mode

What is it?
This is a semi-automatic mode. The user chooses the shutter speed and the camera chooses the aperture. Once again ISO can be set by the user or the camera. The camera still has control over the final exposure.

Who's it for?
Anyone that wants control of motion blur and camera shake but still wants the convenience of an automatic mode.

What benefits does it offer?
Ease of use. Allows control of motion blur and camera shake but still offers automatic exposure.

Manual (M) Mode

What is it?
Full control of aperture, shutter speed, and ISO by the user.

Who's it for?
Experienced photographers who want total control of every image or those looking for the pinnacle of control.

What benefits does it offer?
Complete control over every aspect of exposure. Depth of field, motion blur, camera shake, and noise are all in the hands of the photographer. It also has huge benefits in flash photography but that's an entirely different blog series.

 

If you've never ventured away from full auto mode then the place to start is aperture priority mode. Preferably with a prime lens that has a big maximum aperture. This way you can start to get an idea of how aperture affects an image. Try taking the same picture at one stop intervals and then look at them on a big monitor. Try taking pictures of things up close and far away. Try to focus on different objects in the same frame. Do all of this while playing around with aperture. It's a great place to start. 

 

The Exposure Triangle

exposure-triangle.png

If you don't have a good  understanding of apertureshutter speed, and ISO be sur e to read my blogs on those first.

In a perfect world I would shoot everything at 1/quintillionth of a second (Although we haven't achieved this shutter speed yet, we're getting closer. Watch here) and ISO 100 (or the native ISO of my camera). That way motion blur, camera shake, and noise would all be eliminated and dynamic range would be at it's peak. Then I would choose my aperture based on the depth of field I wanted to achieve and voila! Picture perfection. By now you should know that this isn't reality. Instead there's always sacrifices that must be made.

The three most important variables for any image are shutter speed, aperture, and ISO. These are the only factors that control how bright or dark your image is; the exposure. We've all seen pictures that were too dark or so bright that the subject was indistinguishable. This is because the exposure was incorrect for that situation. With a better understanding of how exposure works you can remedy that problem in the majority of situations. 

All cameras measure light in stops. Likewise, aperture, shutter speed, and ISO are all measured in stops. Every time you increase an exposure by one stop you double the amount of light that reaches the sensor or in the case of ISO the sensor needs 1/2 the light to get the same exposure.

Before we go any further let me give you an example of why the exposure triangle is important. Let's look at three different scenarios. 1) Photographing basketball in a high school gym. 2) Photographing a baby indoors. 3) Photographing a flower just after sunset. To you and me these are three totally different situations. To a camera, they could all be the same. Why? Because the camera only "sees" light, and the lighting in these situations could be the same the way the camera sees it. If you let the camera do all of the work for you it would choose the same exposure for all three situations. Let's say it chooses a shutter speed of 1/50th, an aperture of f/2.8 (the maximum aperture of your lens), and an ISO of 400. This exposure is the correct brightness for all three scenarios. However, it doesn't mean it's what we want to use.

In scenario 1 the players would be moving quickly around the court. An exposure of 1/50th would make all of their movements come out blurry. We'd much rather shoot at 1/400th of a second. This is a decrease of 3 stops (1/50->1/100->1/200->1/400). So if we left the everything else the same the images would come out too dark. It would look like they played basketball in a cave. To counteract this we need to increase the aperture and or ISO by 3 stops. The aperture of f/2.8 is the maximum for our lens. That means we can't make it any better. So in order to get the proper exposure we must increase the ISO by three stops (400->800->1600->3200). Now the ISO is 3200. So the images will have more noise, but the players won't be blurry. Since we counteracted our change in shutter speed with a corresponding change in ISO the image is going to be the same brightness. That's the exposure triangle at work.

For scenario 2 the camera chose good settings. The shutter speed is quick enough to eliminate camera shake and a baby won't move much so motion blur isn't much of an issue. ISO 400 gives us good dynamic range and low noise. The aperture of f/2.8 gives us a usable depth of field.

Scenario 3 could use our help. Since our subject, the flower, is static we don't have to worry about motion blur (unless it's windy). If we use a tripod then we can eliminate camera shake. With those two variables eliminated we can use any shutter speed we want. The aperture of f/2.8 needs to be smaller so that our depth of field is bigger. We want the entire image in focus. So let's decrease the aperture two stops (2.8->4->5.6). Ideally we'd like to use an ISO of 100. That decreases our exposure another 2 stops (400->200->100). If we took a picture at ISO 100, f/5.6, and 1/50th of a second we would get an image that's nearly black. To counter our changes be need to lengthen the shutter speed 4 stops (1/50->1/25->1/12->1/6->1/3). Now our shutter speed is 1/3 of a second, but that doesn't matter because we've eliminated camera shake and motion blur. Now we have an image that is totally in focus, has maximum dynamic range and minimal noise.

 

ISO

Unlike the aperture and shutter, ISO does not physically control the amount of light hitting the sensor. It controls how sensitive the sensor is to light. It's similar to our skin and tanning. Some people's skin is not very sensitive to light. They can sit in the sun for a long time to achieve the perfect tan. Some people have really sensitive skin. When they go tanning it takes very little time to go from no tan to sunburned. Similarly, if a camera is set to a low ISO then it takes a longer time to get the correct exposure (tan). If it is set to a very high ISO then it takes very little time to achieve the correct exposure (tan). The lower the ISO, the longer the sensor must be exposed. In either case, if the shutter is open too long, then the image will be blown out (sunburned) and unusable. It's important to select a good ISO that gives us the perfect exposure (tan).

Generally the ISO on a camera starts at 100. Most of the time it's also the base ISO or the ISO that the sensor is naturally at. Every time the ISO doubles the exposure increases by one stop. So most cameras will have ISOs of 100, 200, 400, 800, 1600, etc.  The ISO does not increase forever. It varies by camera how high the ISO goes. The reason being, the higher the ISO the more noise is introduced into the image. Don't know what noise is? See below.

 

The image on the left was shot at ISO 100 and the image on the right was shot at ISO 6400

Both of the images above are cropped and blown up to emphasize the noise. The image on the left was shot at a much lower ISO and therefore has much less noise and distortion. The amount of noise that cameras have varies. With my first point-and-shoot I wouldn't use above ISO 400 because the images had too much noise for my taste. With my current camera I have no issue with shooting at ISO 3200. That's a big difference. It means I can get great images inside with a couple lamps on. That's not possible with a point-and-shoot.

The other sacrifice you make with higher ISO is dynamic range. I'll go into dynamic range in detail later on, but know that it's the cameras ability to maintain detail in the highlights (the bright areas) and shadows of an image. That's a sacrifice that we have to be cognizant of when shooting at high ISOs.

Remember that low ISOs are better. When you raise the ISO the image quality decreases because you increase noise and reduce detail.

Shutter Speed

The shutter sits directly in front of the sensor on most cameras. It's job is to open and close very quickly to expose the sensor to the light entering through the lens. Shutter speed is the amount of time that the sensor is exposed to light. The sensor is usually exposed to light for a very short period of time. In order to get one more stop of light you must double the time that the shutter is open.  In order to go down a stop (aka cut the light in half) you must also cut the shutter speed in half.

Shutter speed is easy because the way we measure it is exactly how you would think. We use the time that the shutter is open. Usually it's given as a fraction of a second. For example, 1/125 or 1/400. This means the shutter is open for 1/125th of a second or 1/400th of a second. This is way faster than our brains can register. If our eyes were video cameras our shutter speed would be 1/24th of a second. This is one reason photography can be so amazing. It can capture moments we can't see with our own eyes because they happen faster than we comprehend. 

Shutter speed determines motion blur and camera shake. Motion blur is cause by movement in the scene. The faster the shutter speed, the less motion blur. In the picture below notice that everything is in focus except his left hand. That's because everything is static except that hand. Because he was moving and my shutter speed was not fast enough to "stop" his motion I ended up with motion blur.

 

There is not a certain shutter speed that stops all motion. For example, if I'm taking a picture of a tortoise a shutter speed of 1/100th of a second might be fast enough to eliminate motion blur. However, if I'm trying to shoot a 200 mph race car, then a shutter speed of 1/8000th of a second might not be fast enough to eliminate motion blur. It very much depends on the subject. This is something that you need to experiment with and figure out how fast your shutter must be to stop motion. If I'm shooting a motionless person I never shoot slower than 1/50th. If I'm shooting people that are walking and moving around I don't shoot slower than 1/200th of a second. But both of those are the slowest shutter I use. If I had the choice I would shoot almost everything at the maximum shutter speed of my camera (1/8000th). Unfortunately, the only time that's an option is when I'm shooting in direct sunlight, and no photographer wants to shoot in direct sun all the time.

The other reason shutter speed is important is camera shake. When we are holding a camera in our hands it's not perfectly steady. The camera is always moving a little bit. That movement can cause your images to blur. The slower the shutter speed, the more this is exaggerated.

In order to eliminate motion blur and camera shake, we want the fastest shutter speed possible.  Remember that.

I'll keep adding to the blog, but for now go take some pictures! 

Aperture

Aperture is a hole through which light travels. On a lens this hole can increase or decrease in size to allow more or less light to hit the sensor. God gave you an aperture also. Most of us call it your pupil. When you go outside in bright sunlight your pupils get really small to let less light in. The same thing happens on the aperture of your camera. If there's a lot of light then your camera will close down its aperture to allow less light to hit the sensor. On the other hand, if there is a small amount of light then the camera will open the aperture as wide as it can to capture the most light that it can.

 

35mm lens set to a large aperture.

35mm lens set to a small aperture

If you read my earlier post about stops of light then you know we measure aperture in terms of stops. Every time the aperture doubles in size (in terms of area) the amount of light getting through doubles and the exposure is increased by one stop.

We can't use stops to measure the aperture because it is arbitrary. You could define any aperture as zero and move up and down any number of stops from there. This is where the f-number comes in. It's how we measure the size of the aperture. The f-number is based on a ratio. It's (the diameter of the aperture):(focal length of the lens). If you look at the front of your camera lens it probably says something like 1:4 on it. If it's a zoom lens it might look like 1:2.8-5.6. This is the maximum aperture of the lens expressed as a ratio. Because it's a ratio, the smaller the number, the bigger the aperture. Often times you'll see aperture like this f/5.6. This is the most common notation.  Don't forget, the smaller the number the bigger the aperture.

Here's a list of apertures in 1-stop increments: 

f/1.4, f/2, f/2.8, f/4, f/5.6, f8, f/11, f16, f/22

Apertures larger than f/1.4 are very uncommon. There are lenses that can achieve this, but they are few and far between. Lenses with large maximum apertures can be used in extreme low light situations. Aperture also controls depth of field. Don't know what that is? No problem. I'll be covering it in a later post. 

Basically, you need to know a couple things about aperture. It's the size of the opening that allows light onto the sensor, and the smaller the f-number, the bigger the opening. Aren't you glad you read all that when you could have just read this paragraph? Now quit reading and go practice.

A Stop of Light

Photography is all about capturing light. Cameras are built to measure and capture light. It's that simple. What makes it hard is that cameras need a very specific amount of light. If they don't get enough light then the image they produce is dark. If they get too much light then the image is "blown out" or too bright. It's our job as photographers to make sure the camera sees the perfect amount of light. 

To help us with our job, the stop was invented. The stop helps us describe how much light the camera is getting. Increasing by one stop is the same as doubling the amount of light. Decreasing by one stop is the same as halving the amount of light.

Hopefully you know that light is made up of particles. Let's say that your camera is getting 400 particles of light. Yes, that's a gross underestimate of the light particles your camera receives, but I'm told math is easier with smaller numbers. If you increase by one stop then the camera would receive double the amount of light, or 800 particles. If you increase by two stops then the light would be doubled twice and the camera would get 1600 particles of light. Increase 3 stops, 3200 particles. Increase 4 stops, 6400 particles. etc... In the same way, if you decrease by one stop then the camera would receive half the light or 200 particles. Decrease 2 stops, 100 particles. Decrease 3 stops, 50 particles. etc...

That's all a stop is. You can start from anywhere. You could start with 1,434,031 particles of light. If you increased by one stop then you'd have 2,868,062 particles of light. We use this basic idea in all of the exposure controls. Those are, aperture, shutter speed, and ISO. Stay tuned, because those are the topics for my next three blogs.

How to Photograph Fireworks

I love fireworks. Maybe it's because they're explosions, and I'm a man. Maybe it's because I get to channel my inner kid for one night.  Maybe it's because I overcame my childhood fear of them. Doesn't matter why, I love them. So when I started getting into photography I wanted to capture their beauty on film...ahem...in 1's and 0's.

This year my family had the privilege of attending two different fireworks shows on two different nights. The first night I thought we were going to the park for a concert. A certain member of the family forgot to mention the fireworks show. Luckily I had my camera but didn't pack a tripod. Obstacle one, hold a camera steady for 2-3 sec without a tripod. My solution was to plant the camera firmly on the ground and move as little as possible. It worked fairly well, although there is noticeable camera shake in all the images. But that's okay because it adds some flavor. Obstacle two, location. I didn't pick it and I wasn't going to leave my friends for an hour to stake out the perfect location. As a result I decided to only have the fireworks in frame. They were too high to include anything else of interest. Also, adding foreground elements wouldn't have worked with the technique I was attempting. What technique you ask? I'll tell you. When the firework was on it's way up, I set my lens to it's shortest focusing distance. I would start my exposure right before the firework exploded. When it did explode, I would rack my focus to infinity. This way the firework would start way out of focus and about the time it was done it would come into sharp focus. Here's what I ended up with:

I think I could sell the first picture as an exotic underwater creature I discovered in the depths of the Pacific. Then I might make some money from it.

The next night was my chance to control everything. Ever since I moved back to St. Louis, four Independence Days ago, I've wanted to take the de facto STL fireworks shot. The old courthouse and arch in the foreground and the fireworks bursting in the background. This was the year it finally happened. I knew where I wanted to set up, I knew what gear to bring with me, and I knew how to bring it all together. Luckily, I got the shot.

It does add interest to an image when foreground elements are present. It gives context and draws the audience into the picture. It makes the fireworks seem more real. Try it sometime. You have 364 days to plan for it. . If you didn't get out and shoot this year then grab a beer, go sit in the bleachers at Wrigley Field, and join the chant of those around you, "there's always next year."

Here's my quick guide to shooting fireworks (pun intended):

1) Use a tripod. Keep that camera steady. 

2) Shoot manual, and start with an exposure in the 2-3 sec range. Your ISO can be low. I shot the above at ISO 200. The aperture was f/9. Use bulb mode if you have it.  You want to expose the sensor the entire length of the firework.

3) Compose your shot before the sun goes down. Hopefully you know where the fireworks will be. 

4) Get there early and find the best angle. Try to find some foreground interest. 

5) Shoot early in the show, before the smoke takes over. 

6) Play with your exposure and timing.  Try shooting for longer times to get more fireworks in one frame.

7) Make sure you get some good shots before you experiment. Otherwise you might come away with nothing AND you'll have to wait a year for another opportunity. 

The Beginning

I started my photographic journey with an inexpensive, hand-me-down, point and shoot camera. It was a Canon A85. Its best feature was that it allowed manual control. A lot of point and shoot cameras don’t have manual control but this one did which helped me learn the basics of photography. If that's your goal then find, buy, steal a camera that allows manual control. Aperture, shutter speed, and ISO are never going to make sense if you can’t control them and see the affects they have on an image. If you want to begin learning photography start with a camera that allows you to pick the shutter speed, aperture, and ISO. You don’t have to know what any of those things are right now, but make sure your camera can at least do that.

Once you have the camera in your hands, read the manual. Then read it again. Make sure you know how to handle your camera. How do I change the Aperture? Shutter speed? ISO? Manual focus? etc… These are all questions you should be able to answer. Every camera is different and it's important to know how your camera functions. Then you will be able to focus on taking pictures instead of wondering where you have to go in the menu system to change that key setting you want to use. Of course the best way to get to know your camera is to go out and use it. There's no substitute for time behind the lens. So get out there and shoot!

 

This is the first picture I could find taken with my A85. It's the first batter of Game 4 of the 2004 World Series. Johnny Damon is at the plate. He hit a home run in this at bat that later proved to be ther game winning run. Not a great night for us Cardinal fans.

What is This?

I'm starting this blog with two things in mind: 

1) I'm a teacher. I enjoy teaching. I'm also a photographer. I enjoy photography. So this is my attempt at combining those two passions. Unfortunately, I don't have a passion for writing, but I feel it's the best way to share my knowledge at this point. My writing style is in line with my personality; simple and too the point. No extra fluff here.

2) I love to learn new things. By creating a blog, I'm hoping to learn. It forces me to try new things so I can share them with you. 

So here we go. I'm going to start at ground zero, the very basics of photography. I'll share how I started my journey and we'll move on from there.